1. Industrial Field of Use
This invention relates to a conveying apparatus, and more particularly to a conveying apparatus having a conveyor belt driven by rotating drive members such as sprockets.
2. Description of the Related Art
In a wide variety of industries, it is common to transport goods within a factory or other facility on a conveying apparatus having a modular conveyor belt. A modular conveyor belt is formed from a plurality of interfitting modules, frequently made of plastic, which can be joined together to make a belt of any desired length by using a suitable number of modules. Each module includes openings sized for engagement with sprockets, which are mounted on shafts at one or more locations along the path of the belt. The belt is driven along its path by rotation of the sprockets.
Typically, a plurality of sprockets are mounted on a shaft in parallel, with each sprocket engaging the conveyor belt at a different location along the width of the belt. At least one of the sprockets is secured to the shaft-to prevent the lateral movement of the sprocket, while the other sprockets are free to slide or "float" laterally along the shaft. The one or more fixed sprockets provide for proper alignment of the conveyor belt, while the floating sprockets can move along the shaft in accordance with the variations in the width of the conveyor belt. Allowing some of the sprockets to float prevents stresses which would be produced in the conveyor belt were all the sprockets fixed in place.
Various arrangements are used in conventional conveyors to fix sprockets to a shaft, including set screws and retaining rings such as C-rings. These conventional arrangements have the drawbacks that it is usually necessary to cut holes or grooves in the shaft to receive the set screws or retaining rings, and this increases the manufacturing costs of the shaft and also weakens the shaft, causing earlier failure. Furthermore, a sprocket can not be secured to a shaft at any desired location, and can only be installed at a small number of locations where the holes or grooves have been formed in the shaft. In addition, in some arrangements, it is necessary to remove all the sprockets from a shaft in order to remove a single retaining ring.